Well, I didn't find a link to any font package on K Design Works, only a discussion of fonts improvement techniques. I guess, the articles are addressed to Amazon - advice on how to make the fonts look better on eInk. Perhaps it will not fall on deaf ears...

I am certainly not going to design my own fonts, I don't have time for that. If someone sends me a set of fonts (Serif, Sans Serif, Monospace, each in Regular, Italic, Bold and BoldItalic), I can make an update package and put it out for everyone to download.